B-mode subwavelength vibration imaging

Shear wave elastography relies on acoustic radiation force to generate shear wave vibration. In magnetomotive ultrasound (MMUS), magnetic excitation along with magnetic nanoparticles (MNPs) induces magneto-vibration. Both types of tissue vibrations are in the range of few micrometers and not observable in conventional B-mode imaging. Computationally intensive sub-wavelength motion tracking is required to visualize the shear wave propagation for shear wave speed estimation and to localize magneto-vibration sources for mapping MNP distribution. In this study, we propose a novel vibration visualization technique - B-mode subwavelength vibration (B-SV) imaging, which can reveal such invisible vibrations in B-mode images without the need of sub-wavelength motion estimation. Simulations and MMUS experimental data (not shown here) are used to verify the proposed technique. From the results it is easy to locate the vibration source and visualize the shear wave in B-mode images, using the proposed B-SV imaging technique. The proposed B-SV imaging technique provides straightforward B-mode visualization of the originally invisible vibrations. It is expected that the proposed B-SV imaging would be beneficial to the shear wave elastography and MMUS.